emotodude said:
I am the original owner of my 2014 Spark EV, bought in Oct 2013, just ticked over 40,000 miles. Just got back from a short trip and noticed the battery capacity is seemingly getting rather low. By my maths this equates to ~15.3kWh capacity. Time to get it checked at the dealer? What is the warranty threshold?
OK, this is from memory, so it might be wrong ... the 2014 Spark EV battery warranty is for 8 years and 100K miles. The definition of "normal" degradation during that period is up to 35% (for a 2014 - I think that it was raised to 40% for 2015 and 2016). If the battery had a 20kWh capacity when new, that would mean you could lose up to 7kWh (i.e., down to 13 kWh when full) and still be considered "within warranty limits". If you are getting an average of 5 mi/kWh, you would lose 35 miles of full-charge range. Now, that is blurring the lines between "actual capacity" and "usable capacity". The battery may, theoretically, be chargeable from completely empty to 'full' with 20 kWh, but the 'usable' capacity may be lower (say, 18 kWh) because GM made it impossible to really, completely, fully charge or discharge (meaning they left a non-user-accessible buffer zone at the top and bottom, to make the battery last longer. I don't remember ever seeing GM publishing official capacity info on the batteries in the Spark (with the clarification that they were 'theoretical' or 'usable'), but some figures I've heard were around 21 kWh for the 2014 (before they changed battery supplier for the 2015). Usable, I would guess was about 18.5 kWh (since the default m/kWh for the car is 4.4, and 82/4.4 is 18.6).
65% of 18.6 is 12
65% of 20 is 13
What does all that mean? You have until 2021 AND 100,000 miles max to use the battery warranty. And you probably can't get it applied until the usable capacity of the battery is below 13 kWh (a highway range of around 57-60 miles in warm weather, around 75 degrees F).
Frankly, it looks like your battery is doing fine, and what will probably happen is that the battery won't degrade enough to get it replaced. So, you drive it several more years until the range just isn't enough for your usage anymore, then :
1) buy a used (4 or 5 -year old) Bolt with ~180-220 miles range for $10K
2) use the Spark only for around town driving after that (the maintenance is pretty much nonexistent, as you know) OR let a kid or a wife or girlfriend drive it while you drive the Bolt